Epsomite

Epsomite
Mineralogical name	Epsomite
Chemical name	Magnesiumsulfate Heptahydrate
Trivial name	Bitter Salts, Reichardtite, Seelandite
Chemical formula	MgSO4•7H2O
Other forms	Kieserite (MgSO4•H2O) Sanderite (MgSO4•2H2O) Starkeyite (MgSO4•4H2O) Pentahydrite(MgSO4•5H2O) Hexahydrite (MgSO4•6H2O) Meridianite (MgSO4•11H2O) Magnesium 12-Hydrate
Crystal system	orthorhombic
Crystal structure
Deliquescence humidity 20°C	90.1% (20°C), 94% (30°C)
Solubility (g/l) at 20°C	710 g/l
Density (g/cm³)	146.8 cm3/mol
Molar volume	246.48 g/mol
Molar weight	1.67 g/cm3
Transparency	transparent to translucent
Cleavage	perfect
Crystal habit
Twinning
Phase transition
Chemical behavior
Comments	can by produced from an aqueous solution under 50°C
Crystal Optics
Refractive Indices	nx = 1.433 ny = 1.455 nz = 1.461
Birefringence	Δ = 0.028
Optical Orientation	biaxial negative
Pleochroism
Dispersion
Used Literature
{{{Literature}}}

<bibimport/> Authors: Hans-Jürgen Schwarz, Tim Müller, Nils Mainusch
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Hygroscopicity

Figure 1: The system MgSO₄/H₂ form -30°C to 80°C , (Diagram: Michael Steiger)

Table 1:Deliquescence points at different temperatures [after [Arnold.etal:1991]Title: Monitoring Wall Paintings Affected by soluble Salts
Author: Arnold, Andreas; Zehnder, Konrad
]

10°C	20°C	25°C	30°C
86,9% r.F.	90,1% r.F.	88,3% r.F.	88,0% r.F.

Sorption of moisture

Tabele 2: Behavior concerning moisture sorption of magnesium sulfate [after [Vogt.etal:1993]Title: Der Einfluss hygroskopischer Salze auf die Gleichgewichtsfeuchte und Trocknung anorganischer Baustoffe
Author: Vogt, R.; Goretzki, Lothar
]

Moisture sorption at	87%r.F.	81%r.F.	70%r.F.	61%r.F.	50%r.F.
MgSO4	76	75	70	71	27
MgSO4 + NaCl (1:1 molare mixture)	240	146	75	50	20

Salts and deteriotion pattern

Under the polarising microscope

• Crystallized from a water solution on a glass slide
• 

  Sample of a salt crust of magnesium sulfate whiskers

• 

  Real sample with magnesium sulfate salts, crystallized from a water solution on a glass slide

• 

  Real sample with magnesium sulfate salts, crystallized from a water solution on a glass slide

• 

  Real sample with magnesium sulfate salts, crystallized from a water solution on a glass slide

• 

  Real sample with magnesium sulfate salts, crystallized from a water solution on a glass slide

• 

  Real sample with magnesium sulfate salts, crystallized from a water solution on a glass slide

• 

  Magnesium- sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

• 

  Magnesium sulfate, crystallized from a water solution on a glass slide

A phase is a physically distinctive form of matter and is characterized by having relatively uniform chemical and physical properties.